7 our $VERSION = '0.091001'; # 0.91.1
8 $VERSION = eval $VERSION;
10 require Moo::sification;
18 return if $MAKERS{$target}; # already exported into this package
19 _install_coderef "${target}::extends" => sub {
20 _load_module($_) for @_;
21 # Can't do *{...} = \@_ or 5.10.0's mro.pm stops seeing @ISA
22 @{*{_getglob("${target}::ISA")}{ARRAY}} = @_;
23 if (my $old = delete $Moo::MAKERS{$target}{constructor}) {
24 delete _getstash($target)->{new};
25 Moo->_constructor_maker_for($target)
26 ->register_attribute_specs(%{$old->all_attribute_specs});
29 _install_coderef "${target}::with" => sub {
31 Moo::Role->apply_roles_to_package($target, $_[0]);
33 $MAKERS{$target} = {};
34 _install_coderef "${target}::has" => sub {
35 my ($name, %spec) = @_;
36 $class->_constructor_maker_for($target)
37 ->register_attribute_specs($name, \%spec);
38 $class->_accessor_maker_for($target)
39 ->generate_method($target, $name, \%spec);
41 foreach my $type (qw(before after around)) {
42 _install_coderef "${target}::${type}" => sub {
43 require Class::Method::Modifiers;
44 _install_modifier($target, $type, @_);
49 @{"${target}::ISA"} = do {
50 require Moo::Object; ('Moo::Object');
51 } unless @{"${target}::ISA"};
53 if ($INC{'Moo/HandleMoose.pm'}) {
54 Moo::HandleMoose::inject_fake_metaclass_for($target);
58 sub _accessor_maker_for {
59 my ($class, $target) = @_;
60 return unless $MAKERS{$target};
61 $MAKERS{$target}{accessor} ||= do {
62 my $maker_class = do {
64 if (my $defer_target =
65 (Sub::Defer::defer_info($target->can('new'))||[])->[0]
67 my ($pkg) = ($defer_target =~ /^(.*)::[^:]+$/);
68 $MAKERS{$pkg} && $MAKERS{$pkg}{accessor};
75 require Method::Generate::Accessor;
76 'Method::Generate::Accessor'
83 sub _constructor_maker_for {
84 my ($class, $target, $select_super) = @_;
85 return unless $MAKERS{$target};
86 $MAKERS{$target}{constructor} ||= do {
87 require Method::Generate::Constructor;
89 my ($moo_constructor, $con);
91 if ($select_super && $MAKERS{$select_super}) {
93 $con = $MAKERS{$select_super}{constructor};
95 my $t_new = $target->can('new');
97 if ($t_new == Moo::Object->can('new')) {
99 } elsif (my $defer_target = (Sub::Defer::defer_info($t_new)||[])->[0]) {
100 my ($pkg) = ($defer_target =~ /^(.*)::[^:]+$/);
102 $moo_constructor = 1;
103 $con = $MAKERS{$pkg}{constructor};
107 $moo_constructor = 1; # no other constructor, make a Moo one
110 ($con ? ref($con) : 'Method::Generate::Constructor')
113 accessor_generator => $class->_accessor_maker_for($target),
114 construction_string => (
116 ? ($con ? $con->construction_string : undef)
117 : ('$class->'.$target.'::SUPER::new(@_)')
119 subconstructor_handler => (
120 ' if ($Moo::MAKERS{$class}) {'."\n"
121 .' '.$class.'->_constructor_maker_for($class,'.perlstring($target).');'."\n"
122 .' return $class->new(@_)'.";\n"
127 ->register_attribute_specs(%{$con?$con->all_attribute_specs:{}})
138 Moo - Minimalist Object Orientation (with Moose compatiblity)
149 my $amount = shift || 1;
151 $self->pounds( $self->pounds - $amount );
161 die "Only SWEET-TREATZ supported!" unless $_[0] eq 'SWEET-TREATZ'
167 isa => quote_sub q{ die "$_[0] is too much cat food!" unless $_[0] < 15 },
174 my $full = Cat::Food->new(
175 taste => 'DELICIOUS.',
176 brand => 'SWEET-TREATZ',
186 This module is an extremely light-weight, high-performance L<Moose> replacement.
187 It also avoids depending on any XS modules to allow simple deployments. The
188 name C<Moo> is based on the idea that it provides almost -but not quite- two
191 Unlike C<Mouse> this module does not aim at full L<Moose> compatibility. See
192 L</INCOMPATIBILITIES> for more details.
194 =head1 WHY MOO EXISTS
196 If you want a full object system with a rich Metaprotocol, L<Moose> is
199 I've tried several times to use L<Mouse> but it's 3x the size of Moo and
200 takes longer to load than most of my Moo based CGI scripts take to run.
202 If you don't want L<Moose>, you don't want "less metaprotocol" like L<Mouse>,
203 you want "as little as possible" - which means "no metaprotocol", which is
206 By Moo 1.0 I intend to have Moo's equivalent of L<Any::Moose> built in -
207 if Moose gets loaded, any Moo class or role will act as a Moose equivalent
210 Hence - Moo exists as its name - Minimal Object Orientation - with a pledge
211 to make it smooth to upgrade to L<Moose> when you need more than minimal
214 =head1 Moo and Moose - NEW, EXPERIMENTAL
216 If L<Moo> detects L<Moose> being loaded, it will automatically register
217 metaclasses for your L<Moo> and L<Moo::Role> packages, so you should be able
218 to use them in L<Moose> code without it ever realising you aren't using
221 Extending a L<Moose> class or consuming a L<Moose::Role> should also work.
223 This means that there is no need for anything like L<Any::Moose> for Moo
224 code - Moo and Moose code should simply interoperate without problem.
226 However, these features are new as of 0.91.0 (0.091000) so while serviceable,
227 they are absolutely certain to not be 100% yet; please do report bugs.
229 If you need to disable the metaclass creation, add:
233 to your code before Moose is loaded, but bear in mind that this switch is
234 currently global and turns the mechanism off entirely, so don't put this
235 in library code, only in a top level script as a temporary measure while
236 you send a bug report.
238 =head1 IMPORTED METHODS
242 Foo::Bar->new( attr1 => 3 );
246 Foo::Bar->new({ attr1 => 3 });
251 my ( $class, @args ) = @_;
253 unshift @args, "attr1" if @args % 2 == 1;
260 The default implementation of this method accepts a hash or hash reference of
261 named parameters. If it receives a single argument that isn't a hash reference
264 You can override this method in your class to handle other types of options
265 passed to the constructor.
267 This method should always return a hash reference of named options.
271 Define a C<BUILD> method on your class and the constructor will automatically
272 call the C<BUILD> method from parent down to child after the object has
273 been instantiated. Typically this is used for object validation or possibly
278 If you have a C<DEMOLISH> method anywhere in your inheritance hierarchy,
279 a C<DESTROY> method is created on first object construction which will call
280 C<< $instance->DEMOLISH($in_global_destruction) >> for each C<DEMOLISH>
281 method from child upwards to parents.
283 Note that the C<DESTROY> method is created on first construction of an object
284 of your class in order to not add overhead to classes without C<DEMOLISH>
285 methods; this may prove slightly surprising if you try and define your own.
289 if ($foo->does('Some::Role1')) {
293 Returns true if the object composes in the passed role.
295 =head1 IMPORTED SUBROUTINES
299 extends 'Parent::Class';
301 Declares base class. Multiple superclasses can be passed for multiple
302 inheritance (but please use roles instead).
304 Calling extends more than once will REPLACE your superclasses, not add to
305 them like 'use base' would.
312 Composes a L<Role::Tiny> into current class. Only one role may be composed in
313 at a time to allow the code to remain as simple as possible.
321 Declares an attribute for the class.
323 The options for C<has> are as follows:
329 B<required>, must be C<ro> or C<rw>. Unsurprisingly, C<ro> generates an
330 accessor that will not respond to arguments; to be clear: a getter only. C<rw>
331 will create a perlish getter/setter.
335 Takes a coderef which is meant to validate the attribute. Unlike L<Moose> Moo
336 does not include a basic type system, so instead of doing C<< isa => 'Num' >>,
340 die "$_[0] is not a number!" unless looks_like_number $_[0]
343 L<Sub::Quote aware|/SUB QUOTE AWARE>
347 Takes a coderef which is meant to coerce the attribute. The basic idea is to
348 do something like the following:
350 coerce => quote_sub q{
351 $_[0] + 1 unless $_[0] % 2
354 Coerce does not require C<isa> to be defined.
356 L<Sub::Quote aware|/SUB QUOTE AWARE>
362 handles => 'RobotRole'
364 Where C<RobotRole> is a role (L<Moo::Role>) that defines an interface which
365 becomes the list of methods to handle.
367 Takes a list of methods
369 handles => [ qw( one two ) ]
379 Takes a coderef which will get called any time the attribute is set. This
380 includes the constructor. Coderef will be invoked against the object with the
381 new value as an argument.
383 Note that Moose also passes the old value, if any; this feature is not yet
386 L<Sub::Quote aware|/SUB QUOTE AWARE>
390 Takes a coderef which will get called with $self as its only argument
391 to populate an attribute if no value is supplied to the constructor - or
392 if the attribute is lazy, when the attribute is first retrieved if no
393 value has yet been provided.
395 Note that if your default is fired during new() there is no guarantee that
396 other attributes have been populated yet so you should not rely on their
399 L<Sub::Quote aware|/SUB QUOTE AWARE>
403 Takes a method name which will return true if an attribute has a value.
405 A common example of this would be to call it C<has_$foo>, implying that the
406 object has a C<$foo> set.
410 Takes a method name which will be called to create the attribute - functions
411 exactly like default except that instead of calling
421 Takes a method name which will clear the attribute.
425 B<Boolean>. Set this if you want values for the attribute to be grabbed
426 lazily. This is usually a good idea if you have a L</builder> which requires
427 another attribute to be set.
431 B<Boolean>. Set this if the attribute must be passed on instantiation.
435 The value of this attribute will be the name of the method to get the value of
436 the attribute. If you like Java style methods, you might set this to
441 The value of this attribute will be the name of the method to set the value of
442 the attribute. If you like Java style methods, you might set this to
447 B<Boolean>. Set this if you want the reference that the attribute contains to
448 be weakened; use this when circular references are possible, which will cause
453 Takes the name of the key to look for at instantiation time of the object. A
454 common use of this is to make an underscored attribute have a non-underscored
455 initialization name. C<undef> means that passing the value in on instantiation
461 before foo => sub { ... };
463 See L<< Class::Method::Modifiers/before method(s) => sub { ... } >> for full
468 around foo => sub { ... };
470 See L<< Class::Method::Modifiers/around method(s) => sub { ... } >> for full
475 after foo => sub { ... };
477 See L<< Class::Method::Modifiers/after method(s) => sub { ... } >> for full
480 =head1 SUB QUOTE AWARE
482 L<Sub::Quote/quote_sub> allows us to create coderefs that are "inlineable,"
483 giving us a handy, XS-free speed boost. Any option that is L<Sub::Quote>
484 aware can take advantage of this.
486 =head1 INCOMPATIBILITIES WITH MOOSE
488 You can only compose one role at a time. If your application is large or
489 complex enough to warrant complex composition, you wanted L<Moose>. Note that
490 this does not mean you can only compose one role per class -
495 is absolutely fine, there's just currently no equivalent of Moose's
497 with 'FirstRole', 'SecondRole';
499 which composes the two roles together, and then applies them.
501 There is no built in type system. C<isa> is verified with a coderef, if you
502 need complex types, just make a library of coderefs, or better yet, functions
503 that return quoted subs. L<MooX::Types::MooseLike> provides a similar API
504 to L<MooseX::Types::Moose> so that you can write
506 has days_to_live => (is => 'ro', isa => Int);
508 and have it work with both; it is hoped that providing only subrefs as an
509 API will encourage the use of other type systems as well, since it's
510 probably the weakest part of Moose design-wise.
512 C<initializer> is not supported in core since the author considers it to be a
513 bad idea but may be supported by an extension in future. Meanwhile C<trigger> or
514 C<coerce> are more likely to be able to fulfill your needs.
516 There is no meta object. If you need this level of complexity you wanted
517 L<Moose> - Moo succeeds at being small because it explicitly does not
518 provide a metaprotocol.
520 No support for C<super>, C<override>, C<inner>, or C<augment> - override can
521 be handled by around albeit with a little more typing, and the author considers
522 augment to be a bad idea.
524 The C<dump> method is not provided by default. The author suggests loading
525 L<Devel::Dwarn> into C<main::> (via C<perl -MDevel::Dwarn ...> for example) and
526 using C<$obj-E<gt>$::Dwarn()> instead.
528 L</default> only supports coderefs, because doing otherwise is usually a
531 C<lazy_build> is not supported per se, but of course it will work if you
532 manually set all the options it implies.
534 C<auto_deref> is not supported since the author considers it a bad idea.
536 C<documentation> is not supported since it's a very poor replacement for POD.
538 Handling of warnings: when you C<use Moo> we enable FATAL warnings. The nearest
539 similar invocation for L<Moose> would be:
542 use warnings FATAL => "all";
544 Additionally, L<Moo> supports a set of attribute option shortcuts intended to
545 reduce common boilerplate. The set of shortcuts is the same as in the L<Moose>
546 module L<MooseX::AttributeShortcuts> as of its version 0.009+. So if you:
551 The nearest L<Moose> invocation would be:
556 use warnings FATAL => "all";
557 use MooseX::AttributeShortcuts;
559 or, if you're inheriting from a non-Moose class,
564 use MooseX::NonMoose;
565 use warnings FATAL => "all";
566 use MooseX::AttributeShortcuts;
568 Finally, Moose requires you to call
570 __PACKAGE__->meta->make_immutable;
572 at the end of your class to get an inlined (i.e. not horribly slow)
573 constructor. Moo does it automatically the first time ->new is called
578 IRC: #web-simple on irc.perl.org
582 mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>
586 dg - David Leadbeater (cpan:DGL) <dgl@dgl.cx>
588 frew - Arthur Axel "fREW" Schmidt (cpan:FREW) <frioux@gmail.com>
590 hobbs - Andrew Rodland (cpan:ARODLAND) <arodland@cpan.org>
592 jnap - John Napiorkowski (cpan:JJNAPIORK) <jjn1056@yahoo.com>
594 ribasushi - Peter Rabbitson (cpan:RIBASUSHI) <ribasushi@cpan.org>
596 chip - Chip Salzenberg (cpan:CHIPS) <chip@pobox.com>
598 ajgb - Alex J. G. BurzyĆski (cpan:AJGB) <ajgb@cpan.org>
600 doy - Jesse Luehrs (cpan:DOY) <doy at tozt dot net>
602 perigrin - Chris Prather (cpan:PERIGRIN) <chris@prather.org>
606 Copyright (c) 2010-2011 the Moo L</AUTHOR> and L</CONTRIBUTORS>
611 This library is free software and may be distributed under the same terms